The purpose of earthquake engineering is to design safety structures that perform satisfactorily under earthquake action. As Japan is one of the most earthquake-prone country is the world, the technological innovation for earthquake resistance design, seismic isolators and vibration control demper etc., has been advanced. Especially the seismic technology, that the seismic isolated buildings demonstrated the effect in the Koe earthquake, so the seismic technolgy is noticed now. In this study the characteristics of the seismic isolation bearing of sliding type have been experimentally investigated. The value of coefficient of friction has important role for the characteristics of seismic isolation of sliding type and the seismic isolator of sliding type has the three factors related to the coefficient of friction μ. From the experiment of Kobe earthquake wave, it has been shown that the acceleration of the seismic isolator does not exceeded the value of μ G that is one of the three factors.